Generally, a secondary battery may be rechargeable and have increased capacity. A representative example of the secondary battery includes a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and the like. Among them, the lithium ion battery has been spotlighted as the next generation power source due to excellent characteristics such as long lifespan, high capacity, and the like. Among them, the lithium secondary battery, which has operating voltage of 3.6 V or more, is used as a power supply of a portable electronic device or several lithium secondary batteries are connected in series with each other to thereby be used for a high output hybrid vehicle. Since this lithium secondary battery has operating voltage three times higher than that of the nickel-cadmium battery or the nickel-metal hydride battery and is more excellent in view of energy density characteristics per unit weight than the nickel-cadmium battery or the nickel-metal hydride battery, the use of the lithium secondary battery has been rapidly increased.
The lithium secondary battery may be manufactured in various types. A representative type of the lithium secondary battery may include a cylindrical type and a prismatic type that are mainly used for the lithium ion battery. A lithium polymer battery that has been recently spotlighted is manufactured in a pouch type having flexibility, such that it has a relatively free shape. In addition, the lithium polymer battery has excellent safety and light weight to make portable electronic devices slim and light.
The pouched type secondary battery cell as described above is configured to include an electrode assembly, a terminal connecting a power supply to the electrode assembly, and a case sealing the electrode assembly so as to expose the terminal to the outside.
The terminal is a component exposed to an outside of the case and the battery cell according to the related art has a disadvantage in that an overall length in a height direction of the case is long while the terminal is exposed to the outside of the case.
Therefore, a development of the battery cell to solve the above problem is required.